Shi et al. showed that serum DKK-1 level is positively correlated with lymphatic metastasis and is indicative of poor prognosis during ICC, and noted that the optimal cutoff value of DKK-1 for detecting CCC was 2490 pg/mL (sensitivity = 75.7% and specificity = 100%) [15]. The gene discussed is DKK1; the disease is intrahepatic cholangiocarcinoma.